


don't let me be the last to know

by cakecakecake



Category: Fire Emblem: If | Fire Emblem: Fates
Genre: Brother/Sister Incest, Explicit Language, F/M, First Time, Masturbation, Oral Sex, Pre-Series, Pseudo-Incest, Vanilla, pre-release
Language: English
Status: Completed
Published: 2015-07-10
Updated: 2015-10-05
Packaged: 2018-04-08 14:41:32
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 10
Words: 12,218
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4309089
Author URL: https://archiveofourown.org/users/cakecakecake/pseuds/cakecakecake
Summary: <blockquote class="userstuff">
              <p>only now they're not sure they're just playing games anymore.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> i am trash ok i am so sorry. i am so sorry. is it 2016 yet god i'm gonna look back at this and beg for repentance

Her bedchamber is only around the corner from his. If he waits another few minutes, Jakob will be finished dropping off her clean nightclothes and tea and he won't need to awkwardly explain why he's wandering the tower so late--he's already prepared an excuse (going to the library, of course), just in case, but he'd rather not see him all the same. His breathing shallows as he listens for footsteps clacking down the hallway. Faintly he can hear her humming to herself, a soothing melody he's not sure he's heard before but makes him feel nostalgic for…something. 

The door is closed all the way shut tonight--but there's a small keyhole that if he bends down, he can…no, he shouldn't--but how is this much different than peering through a door already ajar? He promises himself only a peek, a few seconds just to see what she's up to--

His heart leaps up to his throat. O-oh. Gods. Oh.

Corrin is sprawled out across her satin bedding, lacy nightdress hanging off her shoulders. Her breaths draw in heavily, slowly, like she's bracing herself. Her hands wander up and down her stomach and settle over her crotch. She starts slowly thrusting up into her palm, massaging herself through satin garments. Her perky breasts spill from her gown and she starts playing with them too, her petal-pink nipples hardened. She moans fervidly and Leo feels his knees buckle; every ounce of blood in his body rushes to his groin and he feels his cock pulsing so much it aches. Corrin's hair is mussed across her sheets and sticking to her glossy skin, mouth gaping open as she huffs and puffs and grinds into her hand. Her legs twitch and she turns herself over and grabs a pillow to start humping into vigorously, grasping at the blankets and groaning. Leo's heart hammers so hard he's sure it'll break through his armor--it's taking everything in him to resist pumping his cock right in the corridor but he mustn't make a sound, he can barely allow himself to breathe--

She's thrusting so hard now, biting into her fist--it looks like she's close. She throws back her magnificent head, silvery blonde hair tumbling around her shoulders and he feels his pants tighten around him as she cries, "L-Leo... _Gods_ , _Leo_ \--"

He gasps and he's sure that she must have heard him--he whirls around on his heel, hurrying back around the corner to his chamber, ready to call for a nurse for he's certain he's going to vomit due to either his painful erection or his shame, he doesn't know which. Regardless, he grabs hold of his length immediately upon closing his door, cumming faster than a teenager just discovering a touch to his cock. This isn't right--this is horribly, _terribly_ wrong--but he can't bring himself to care, not when Corrin's voice sounded so silken saying his name like that...But was it a mistake?

Leo cleans himself off, staring at himself through his vanity glass. Perhaps he had just been imagining it--hearing things. Maybe it was an accident--maybe she hadn't meant to say his name, and it had just spilled out. Gods know he'd mumbled names he'd rather not repeat while pleasuring himself…but what if it wasn't? What if she was--teasing him?

_There's no way_ , he thought, carefully retracing his steps in his mind. There's no way she could have realized--he'd been so careful, so quiet--not a soul would be able to prove he'd spied on her. Unless--

Jakob told her? No, he couldn't know--he hadn't crossed the butler's path outside the dining halls in weeks…There's no way she could know, unless she'd heard him, short, bated breaths in the hallway? Noticed his shadows on the stone walls? What if she'd left her door only slightly open on purpose, knowing he could walk past from around the corner at any time?

_Hmph_. If a game is what she wants, well. He's happy to indulge his pretty elder sister.


	2. Chapter 2

**Notes for the Chapter:**

> honestly? honestly

Corrin's footsteps echo down a lonely corridor in the upper east tower. Jakob had escorted her back to her chambers and bid her goodnight an hour ago, but her mind is too restless for sleep. He's gone to bed himself by now, several staircases below her--she won't pass him on her way to the library. She can't bear to be alone with her thoughts tonight.

Leo had been absent from all their activities today. They were supposed to go riding through the vineyard with Elise, but he was nowhere to be found. They were due for a supplies run, but he never met them at the markets. None of the maids or his retainers had seen him; Zero had been completely unhelpful in finding him and Odin was far too distracted to hold a conversation longer than five minutes without getting derailed, so when he didn't turn up for dinner she jumped to the worst conclusion: he'd heard her last night.

Her stomach churned, remembering hearing footsteps shuffling from the doorway, the faint inhale of surprise (and probably disgust). She wants to think she had just been imagining it, but it was entirely plausible. He'd _definitely_ heard her howling his name at her peak like a starving dog. Why else would he have made himself so scarce today?

Tears are burning in her eyes as she creaks open the door, cursing herself. She just _had_ to moan his name aloud, didn't she? Wasn't it awful enough that she was thinking about him, her younger brother, blood of her blood? Was it not enough to just _imagine_ how good it would feel with his name on her tongue in the throws of her climax? His open mouth on her skin, ravishing her with toxic kisses, magicking the happiness out of her? His deep, dark eyes, looking lustfully over her every curve, his breath hot and heavy at her center, warm hands running over her--

" _Gods_ , damn me," she breathes, almost dropping her candle. She slides behind a bookcase and presses her free hand to her greedy clit, submitting herself to these dirty daydreams of her beautiful brother, her heart catching in her chest.

How would his hands feel, here? Are they as calloused as Xander's? Or softer, like their sisters'? Would he carry a more gentle curiosity or would he--

"Corrin?"

 _Fuck! Gods, fuck_ \--"L-Leo--!" 

"Studying in the middle of the night? I admire your dedication." 

"Sh-shut up," she hisses, smoothing out her nightgown. "What are you doing here? Where have you been all day?"

His eyes shift. "Here."

She glares. "Seriously."

"You asked and I answered. Now what are _you_ really doing here."

Swallowing hard, knowing full well she can't exactly say she was _studying_ \-- "I--couldn't sleep. I thought books would make me feel…less trapped with my thoughts."

"If something is troubling you, _Sister_ ," he says, with venom, "you don't need to suffer alone."

"Leo…" She starts, but doesn't know where to end--by apologizing? Assuming she was right, but…maybe he just wasn't feeling well? He had been behind in a lot of his studies, perhaps he just needed a day to catch up? What if he _didn't_ know? And yet… 

There's something about the way the candlelight flickers in his eyes: like he knows something, something he shouldn't. She feels hollow, like he can see right through to her heart. Slightly, ever so slightly, he smiles.

"I know, Corrin--" her heart _drops_ , but then-- "I'm sorry about the vineyard. I'll make it up to Elise tomorrow."

Breathing never came easier than in that moment-- "It's--it's alright, she...actually wasn't that upset, but--thank you, L--"

His hand is suddenly in her hair. She freezes, lungs emptying of air as he runs his fingers delicately over the hairpin behind her ear. He follows the curve of her cheek with feather-light touches, all the way down her jaw. Her heart rate jolts as he stops with his thumb at her chin. 

"I'm glad you still wear this," he hums, lips curling up at the corners, admiring the hairpiece. A gift from him, of course, years ago when she turned eighteen. Her face flushes red-hot as he turns on his heel. He reaches the doorway and doesn't look back at her when he tells her, "Don't stay up too late, Sister."


	3. Chapter 3

**Summary for the Chapter:**

> i tried so hard to just make this entire work just a pwp but i can't resist angstporn

**Notes for the Chapter:**

> family, duty, ~~honor~~ fucking

It was not nice to tease his older sister like that.

He shouldn't be, but he's more than a little proud of himself. The hairpin-touch was an excellent tactic: subtle, but enough to leave her wanting more--and now it's more than obvious that she does. Had he stayed hidden, he wonders if he would have heard her whispering his name again? If he'd watched from between novels only shelves behind, would he have witnessed another climax dedicated to him? Did she miss him that much today that she just _had_ to touch herself? 

He takes the longer route back to his bedroom, ignoring the swelling in his lounge pants and hoping he doesn't cross paths with any night-attendants. He hopes to seven heavens he isn't just seeing what he wants to see. When he was younger, his… _interest_ in Corrin was easily explained by adolescent curiosity: harmless fascination and inquisition. Both his older sisters were wondrous beings to him, mesmerizing, like moving works of art both at home and on the battlefield with their flowery perfumes and polished weapons--but his attachment to Camilla never became more than that: appreciation. With Camilla, his interests remained innocent, despite her allure.

But with Corrin…curiosity was no longer an excuse to watch her getting dressed through cracked-open doors. Fascination was not the word for what he felt when he watched her tying up her hair. Appreciation was not the word for what he felt when he watched her lick her lips after sipping wine at dinner. It's only natural to admire your siblings; wanting to _fuck_ your siblings is a different story. 

It was a common thing, in the olden days. Many royals in early Nohrian history bedded their family members to keep the bloodline pure, but as time went on, the need to marry within the family tree faded, and the weddings between siblings stopped. The fucking didn't, of course, but when times changed, so did rules. It was unlawful now, to marry the blood of your blood--and while getting caught pounding into your sister in the dungeons wouldn't get you hanged, it could certainly cost you the trust of the rest of your family…if they were to find out.

 _Gods_ , Leo scolded himself, sinking against his bedchamber door. _What am I thinking? These feelings…what cruel Gods would have it so?_

*

It's the third day in a row that Corrin has spent in bed and it's taking both Jakob's and Felicia's strongest efforts to keep her siblings from tearing down the walls to her bedroom. The _she's-contagious-masters-you'd-best-stay-away_ can only really keep Elise at bay, but Xander and Camilla Will Not Have It. Between the two of them nearly dragging her by the hair for dinner the night before and Elise having a crying fit when she refused to take a midday bath with her, Corrin wonders if feigning ill to avoid Leo is really worth it (though considering the only thing she's done in three days besides sleep is fantasize and masturbate, she's guessing not). _Just until I sort these ridiculous feelings out_ , she had told herself, but after a few sunsets alone with her daydreams, she realizes there's no denying it. 

She lusts for her brother, truly and genuinely. Everything about him is so truly captivating: he's so elegant and graceful and strong, beautiful and charming. His undeniable talents, his impressive knowledge, his dedication to his family--everything about him she's adored since he was young, but now that's he's grown… 

Corrin wrings out a towel from the basin and dabs at her face. Gods, her eyes burn from all the tears, her skin is a mess from sweating and crying so much. How could she be so cruelly selfish? Her brother loves her, admires her--expects her to watch over him; how can she if all she wants to do is _fuck_ him so much?

 _I've got to stop_ , she tells herself. She bears a responsibility: a duty to her siblings. She vowed long ago, to protect her brothers and sisters from anything. Nothing should stain the bonds between them--she couldn't bear it if she were to cause a rift amongst them. Her sweet family deserves the best.


	4. Chapter 4

**Summary for the Chapter:**

> and with a kiss we further our descent.

Leo is the only one who doesn't check up on Corrin while she's sick. The others don't notice this; they're far too busy worrying about her to wonder why Leo keeps excusing himself from meals early to go hide in the library. He can't stand to listen to Camilla whining about how much she misses her without feeling the urge to vomit (honestly, it's barely been three days, even he's not being _that_ pitiful), so he buries himself in his studies, trying his best to distract himself from his guilt. 

She had not responded the way he'd predicted: not with touches under the dinner table or teasing winks from the opposite end of the hallway. Not by humming love songs around him or waiting to peel off her armor until she was sure he'd be looking--none of the fun he'd imagined. Instead, she'd shut herself up in her room and feigned illness to avoid confrontation like the annoyingly noble older sister she was, sinking his shameful heart whilst struggling to tame her own.

She's probably worried that he hates her, the fool. She's probably horribly embarrassed and guilty, believing she's betraying his trust without the faintest clue how he's feeling. Leo grunts to himself. He's got to apologize, for spying on her, for teasing her--she'll hate him, but it's the only way they can move past it. She'll never allow herself to act upon her sinful desires, but he cannot allow her to mope around feeling sorry for herself--her happiness is more important. It always has been. 

He must protect his sister's happiness.

*

It's only hours before dawn and sleep won't come to her. All she can think of is her brother's dark violet eyes, glinting in wavering candlelight; knowing, mocking her. She imagines him telling her awful things, calling her dirty, telling her he hates her--she wipes her tears. She knows he could never hate her but…what she's done is damnable, and she must own up to it. She's got to apologize to him directly, not hide away and blindly hope he's forgotten all about it--her poor brother probably can't escape the filthy visages she's planted in his mind. She doesn't deserve it, but she hopes he can forgive her.

Thunder booms from somewhere not far off as she slinks down into the castle gardens, praying the fresh rainy air helps clear her head. Rosebushes soak up the heavy rainfall and small trees and shrubs sway to and fro, their branches twisting around the archways, the soil damp under her bare feet. Corrin wades waist-deep into the pond, running her hands under the fountains, relief washing over her as the rain keeps pouring and splashing around her. She rests with her feet on the rocks, watching her soaking nightdress glide atop the gentle waving water, raindrops hitting the silk like tiny arrows. She turns to face the castle, watching curtains billow in the open window frames when lightning strikes, suddenly illuminating a figure nearing the archway.

Corrin dives behind a cherub statue just large enough to shield her, but it's already too late: he's there, arms folded, sighing with censure. 

"You dingbat. Now you're _really_ going to get sick."

Flushing scarlet, Corrin gathers her wet nightdress and plunges herself underwater far enough so that only her head is above surface. "L-Leo!" 

"You know," he snorts, "for how well you look after your siblings, you certainly do an atrocious job of taking care of yourself."

"I can take responsibility for myself just fine," she barks back, her brows knitting together as she pouts.

"Is that so?" he taunts. "Then why did you shut yourself up in your room for three days straight?"

Suddenly the water feels icy. She hugs herself tightly, drifting around in the water dolefully. "I suppose…it doesn't surprise me that you knew."

"Sister," he speaks gently, and it tugs at her insides-- "I speak only out of concern. I need to--"

"I can't," she croaks--oh, it's _pitiful_ but she feels them brimming up, the hot tears-- 

"Come out of the pool, Sister--"

"No," she protests, choking, "I'm staying right h--"

She turns around just in time to see (--fuck, her heart catches--) him slowly, delicately begin to undress himself. 

He unchains his cloak from across his chest, and it gets tossed on top of a shrub; he pulls his pants down over his long, sculpted legs, and off from around his ankles. He undoes his white nightshirt, button by button, from top to bottom, then grabs his smaller undershirt from the hem and pointedly, while holding her gaze, pulls it up over his head, shaking the winsome blonde hair out of his eyes, leaving himself only in loose-fitting smallclothes. With his eyes still on her trembling figure, he wades into the pond, smiling ever so slightly. 

"Fine," he mutters, "we'll stay right here."

Small sobs bubble in her throat as she feels goosebumps crawling over her flesh. "Leo…"

"There's something I must confess," he begins, but she stops him. 

"No, I know," she whimpers, half-smiling. "I know what you've seen, and I'm so sorry--"

"Sister..."

"You must be so disgusted with me," she says tearfully, "but it's been so, _so_ hard to look at you, ever since you'd grown up."

He moves to push the wet hair out of her eyes, but she turns away. "Leo--I'm so sorry, you have such a pathetic excuse for an older sister--"

"Sister, that's not--"

"I've brought such shame to you," she admits, "Gods, if the others knew, how disgusted would they be?"

"Sister, please--"

"I can't face them--I can't face _you_ until I atone for these filthy feelings, so please, Leo, forgive m--"

It happens so quickly that she almost thinks she's being struck by lightning. There's a splash of water and then suddenly, his hands are grabbing her hair and his _mouth_ \--Gods, fuck, his lips are upon hers, wet and warm, hurriedly and fervidly kissing her. Her eyes fall closed and she's not sure she's breathing anymore but with Leo sighing into her mouth she doesn't think she'll need air ever again. Her hands shakily wind around his waist and he pushes his chest into hers, his tongue sliding across her teeth. She sloppily lets her tongue explore his mouth and he whines impatiently, fists tangled in her moonlit hair. The tears are coming again, she feels them slowly roll down her cheeks and it's when they drip into their mouths that Leo pulls away, chest heaving against hers. 

"Si-Sister..."

She swallows hard, laughing hollowly. "You shouldn't…tease your sister like that."


	5. Chapter 5

**Summary for the Chapter:**

> "what _are_ you planning to do to your little brother?"

**Notes for the Chapter:**

> how the fuck do you write blowjobs

"You shouldn't tease your sister like that." 

There's a pull at his heartstrings as he looks into her tearful face; the magic overwhelming him mere seconds ago has vanished as quickly as it arrived. His face falls. "But I…"

"Leo," she hiccups, "you're sweet, to want to make me feel better, but--" 

"Wait," he insists; his hands find hers and he can't resist pulling her closer. He presses his lips to her forehead and her breaths shorten, quaking in his embrace. "Please, listen to me--I wasn't teasing you, but…I am not without fault, here."

"W…what do you mean?"

A knot forms in his throat as he feels a dire need to cry, like a misbehaving child admitting to a horrible mistake--but he cannot allow himself to, not in front of her. He tries to swallow but nearly chokes instead. "Sister--you do not endure these culpable feelings alone."

Corrin breaks away to meet his eyes, mouth agape in disbelief. "B-Brother…?" 

When he's sure she doesn't seem disgusted, he continues, "It's true. You'll be angry with me, but…I can't let you be angry with yourself, not when I've been spying on you."

"You've been _what_ \--"

"I'm as guilty as you consider yourself--or more," he admits, his stomach churning restlessly. "I've been…watching you for years now--innocently at first, like looking at you for far too long while you studied, but…" 

She's white as a sheet, but she doesn't tear her gaze away; instead she seems--expectant-- "Recently, I've waited until your servants leave your chambers, and watched you sleep, but when I caught you pleasuring yourself--"

"Leo--!"

"I was _thrilled_ , Corrin," he confesses breathlessly, feeling a tear drip down his face. "When I heard you saying my name…I thought you knew. That you realized I had been spying…I thought it to be an initiation--a game to see who would crumble first--"

"Brother…" 

"I was so selfish with my ridiculous expectations," he goes on, "I should have realized that you'd never be as careless as me--"

Two of her dainty fingers press to his mouth as her other hand wipes away the wet trail his only tear left. It makes him feel childish, but at the same time--it's so exciting to have her hands on him. "Shh…hush now. Hush Leo…" 

"Will you forgive your arrogant little brother?"

She's pink in the face again, the lines around her mouth softening. "If you will also forgive me…"

"There's nothing to forgive," he swears, and presses a kiss to her mouth again, but she doesn't move to return it.

"Leo…what will we do now?" 

He knows he shouldn't get hopeful, but his heart is already pounding, ignoring the possible dangers of continuing--whatever it is this might be, hoping she's thinking exactly what he is-- "Wh-whatever you'd like, Sister."

Her eyes are fixated on him as she smiles helplessly. "There are many, many things I'd like to do now…" 

_Gods, me too_ , he sighs to himself--

"But it worries me," she muses, furrowing her brow. "I don't think the others will accept this…"

Her words sting like arrows to his heart, but he tries to seem nonchalant. "It isn't exactly _treason_ ," he states plainly, but she cocks a suspicious eyebrow and then he shakes his head. "But I agree…I don't care to see the look on Brother's face if he were to find out about...this." 

"Leo," she almost whispers, tilting her head up (Heavens, her eyes are sparkling; she's lovely, so lovely), "I want you to remember…we are a family above all else, and I will do what I must to protect everyone."

"Mm-hm," he agrees sourly, but her hands are wandering now: sliding over his biceps, up and down his stomach, roaming his bare chest--she probably feels his heart thumping like mad under her fingers--

"So…if you make it difficult for me to keep composure around them," she smirks, thrusting herself forward, "I'll have to make you pay for it later, do you understand?"

He clears his throat sternly as he feels the water around them getting warmer, her hips dangerously close to his. "D-Don't think you'll have any right to complain if you do the same to me--"

"Brother," she coos, "if we're done forgiving each other…please, come to the library tomorrow. Late, after Jakob has gone to bed."

"The library?" he repeats slyly. "Why."

"I'd like my brother to teach me a lesson."

*

Blood pumps hard in Corrin's ears as she pushes the door to the library open. It's dim inside, only the stars through the windows illuminate the dusty shelves. Amber candlelight glimmers in the far corner past the collection of ancient runes and old Nohrian folklore--he's waiting there like a faithful younger brother, still in his battle gear from earlier that evening. She wants to scold him for not having stopped to rest first, but her nerves are buzzing with anxious delight--she's never been happier to see him. He catches her eyes, smirking impishly.

"Right from a mission?" she gibes. "So impatient."

"Don't badger me," he bites back, "it's only because I didn't feel like taking all of this off, it's tiresome--"

She licks her lips, backing him against the wall. "--so you thought you'd have your big sister take it off for you, then?"

She can see him flush a brilliant shade of magenta in the shadows and her heart rate spikes, _fucking hell_ , what Gods have blessed her with such an adorable little brother? She swears she'll sing their praises when her mouth isn't busy doing something else but now, she plants a wet, earnest kiss on his jaw and sinks her hips into his. Her fingers fumble with the buckles and ties of his armor and he swallows audibly. 

"Your hands are…so warm, ahh I love it…" 

My my, his voice is so low and husky now. She pauses between pecking her way down his neck-- "L-Leo…when did you start sounding like _that_ \--"

She feels his smile curve under her fingers. "When I grew up."

Corrin moans hungrily into his ear as his breaths start coming in shorter, deeper. She nibbles at the flesh behind his earlobe, smoothing her hands over his chest as it rises and falls rapidly. Her fingers wander under his skirt, fiddling with his belting, palming at the front of his pants underneath. He groans ardently and clings to her waist.

"What _are_ you planning to do to your little brother?"

 _O-ooh, fuck_ \--her clit tingles as blood rushes to her cheeks. She boldly starts grinding into his swelling hard-on, teeth pressing against his pulse as it rabbits wildly in his neck. He's panting with fervor now, trying desperately to get her to kiss him, but she's got to get him out of all that troublesome armor first. She peels off shoulder plates, elbow pieces, unbuttons his skirt--all while he's moaning helplessly, his erection twitching under its constraints. Corrin takes her time, relishing his pleading eyes and feverish whimpers. Her prim and proper little brother is coming undone before her and it's making her blood boil.

"Y-you're being unfair," he snivels. "Touching me all over without one kiss--"

"Oh, a kiss?" she says airily, tossing the last piece of his armor to the floor. On her tiptoes, she breathes an inch away from his mouth, tasting the heat of his breath. "I'll give you one, then."

Corrin drops to her knees and Leo barely croaks out "What are you--" before dissolving into a staccato of growls. She mouths at his cock through the fabric of his pants, tongue flat against his bulge, gripping his hips to bring him as close as she can. Leo grinds into her face, winding his sweaty fingers in her hair.

"C-Corrin, you're--you're--you don't need to--"

But she's already yanking his pants down. The sight of Leo's bare, dripping length sets fire to her loins and she's already salivating when she takes all of it in her mouth. Leo howls, biting into his fist to prevent himself making too much noise--Corrin swirls her tongue around his cock like she would with candy. Her canines nip at him here and there and he squirms, breathing so erratically and heavily she's almost worried he's going to pass out--

"S-Sister, use your hands too," he tells her, and she obliges, sucking at his tip while her hands move the base. She hasn't the foggiest if she's doing this right, or wrong, but the moans escaping her brother's throat are all the encouragement she needs, so she keeps bobbing her head, drooling all over Leo's pulsing cock.

"S…Sister," he starts, voice trembling, "Sister, I'm getting very--I'm going to--"

 _Yes_ , she hums, her mouth vibrating around him, _yes, cum for me, little Leo_ : she only flinches a smidge when his hot cum floods her mouth and seeps down her throat. She chokes just a bit, forgetting that she's got to breathe through her nose, but she swallows most of it, only one line of semen dribbling from the corner of her mouth. With a small victorious giggle, she rises to her feet as he pulls his pants up, skin glistening with sweat. He reaches out and wipes her face with his sleeve.

"I'm sorry," she says, still coughing a bit. "I was--very sloppy--"

"You took me by surprise," he breathes, chest heaving. "I--I'm not used to this kind of thing…" 

She worries, suddenly. "I hope I'm not being too forceful--"

He shakes his head, hair falling in his eyes, blush creeping back across his nose. "No, I--I _loved_ it."

Corrin's heart melts upon gazing at his tired, blissful face. With her hands in his hair, she gently kisses his neck again. "You must be so exhausted--I'm sorry, I'd asked you to teach me a lesson but I've worn you out…" 

"There will be time again," he hums. "Whenever you wish it, call for me."

He gently, sweetly kisses her goodnight, and they linger like that for a while, neither wanting to break their embrace, but the night attendants will begin patrolling soon, and they mustn't be caught alone together this late at night. Corrin holds tightly to his arm as they sneak back to their tower, eyes following him as he retires to his dark chambers.

**Notes for the Chapter:**

> definitely threw in a few myroom lines, they're just so _titillating_ \--i really do hope they keep some of them the same for the english version (it's probably obvious which line is my fave). very very excited to be adding more chapters, leo is very very fun to write...and think about...sighs


	6. Chapter 6

Corrin's heavy lashes bat against her reddening cheeks as Leo trails the pads of his fingers down her neck. He's got her backed up against the wall, her breath smelling of cinnamon and butter cookies warm against his lips as she rocks into his hips. Jakob's footsteps down the corridor are only just now fading to silence as he grinds his swelling length into her thigh, winding fingers in her hair messy from sleep. Morning had woken him from a lustful slumber and he'd boldly slipped into her room without a word and with only one thing on his mind. 

"Do you want me?" He groans, sliding his hands up her nightdress to find his answer--her panties are drenched. Corrin whines into the crook of his neck-- "Oh I _know_ you do…I want you so much, it's driving me crazy too--"

With a swift lunge forward, Leo pins his pretty sister to her bed, seizing her wrists high above her head as he litters her neck and chest with wet, heated kisses and bites. He sucks at her sensitive flesh, thrusting his aching hard-on into her groin and she bucks her hips back, sighing and moaning his name, pulling at his hair. He claws at her chest, nearly tearing through the fabric to grab her breasts and she squeals in delight, muttering "that tickles" when he brushes over her nipples. He shoves a few fingers in her mouth to occupy her so he can suck on her tits in peace and she drools on his digits, giggling playfully. Red-and-purple blemishes stain her milky white complexion as he nips and pricks her sweet skin, leaving a trail down her soft stomach on his way to breathe in the musk of her arousal, loins alight with the burning desire to drink her pussy like tea. He gulps, palming at her soaked panties and she writhes under him. She chews on her bottom lip.

"Leo…"

He rubs her silk-covered clit, licking his lips as he watches her furrow her brow, lifting her hips up. He grabs her ass, holding her gaze as his teeth pull down her garments. Grey silken underwear slides down her thighs and Leo captures her wetness with his mouth before it seeps onto the sheets--Gods, she tastes as sweet as he could have hoped. 

He darts his tongue in and out of her entrance, digging his nails into her ass as she muffles her moans with a pillow. One, two, three of his fingers slide into her walls and she thrusts upward, arching her back in heat. Leo wipes his mouth, pulling her upright with his free hand. Gently, cautiously, he kisses her, letting her taste herself on his lips. A line of spit still connects them as he pulls away. 

"You taste _so good_ , Big Sister," he swoons, dizzied with lust. Slippery fingers pump her harder, thumbing over her clit in a quick rhythm. The front of his shirt is balled up in her fists as she pulls him closer, bucking into his hand earnestly, but he pushes her back down, free hand at her throat as he slides the other one out of her. Pointedly, slowly, he licks his fingers clean, one by one, eyes piercing her as he watches her pupils dilate into savage slits. She lets out a guttural, feral moan and clenches a fist around his throat, earning herself an amused coughing laugh from him.

"Leo--don't--be so mean--"

He rolls his hips into hers torturously slowly-- "Mmm? If you want me to touch you, just say so--"

"Leo," she garbles, " _touch me_ , Leo--"

"Touch you?" he repeats, tightening his grip on her throat--he's gyrating on top of her now, only the thin fabric covering his cock separating him from her sex-- "How?"

She humps right back up into him, face completely flushing. "Brother--" (Mmm, her voice gets so husky when she says that) "--I want you to--to--"

"Yes?" he teases, hands smoothing down to squeeze her perky breasts--she grins sinfully, eyes ablaze as she moans at him--

"I want you to _drink_ my _cunt_ , Little Brother."

 _Fuck_.

Leo can't dive down quick enough--he laps at her center, gripping her thighs as she clamps them around his head, thrusting into his mouth with his name on hers. He moves his tongue in quick zig-zags around her sex, sliding fingers inside and out as she clenches. Corrin bucks her hips, tugging on his hair and telling him faster, yes, harder, harder, almost screaming when he sucks her clit so acutely that he swears she's going to--

"Leo I'm--! I'm--!" 

She's throbbing against his tongue--she cums all over his mouth, her sweet wetness dripping down his chin. He slowly licks her up, making out with her cunt as she rides her climax out to the very last throw. Her legs are shaking, chest heaving as he kisses his way up to her neck, tasting her fluttering pulse while he tries to get his to calm. He settles on top of her, his still-very-hard cock aching in its confines. Corrin plays with the waistband of his pants, smirking. 

"It's your turn."

**Notes for the Chapter:**

> i think i've rewritten this chapter about five times ¯\\_(ツ)_/¯ happy with how it turned out tho


	7. Chapter 7

_"He loves you."_

_"Yes, of course he does--he's my brother--"_

_"Don't take me for an idiot, princess. You know exactly what I mean."_

*

Leo's mission on Hoshidian ground ends abruptly after an archer misses Corrin's back by merely a hair. In a childish fit, he strikes spiking roots through several soldiers' heads with his formidable spells to retaliate, ignoring the several enemies now hounding his brother and his subordinates. He hurries to her side to assure that she's unharmed, nearly costing Xander the lives of his dear Peri and Laslow had they not been blessed with impeccable reaction timing. Xander had been so distracted with keeping his retainers' heads on their shoulders that he barely misses catching sight of the desperate and passionate kiss he thoughtlessly plants on his sister in front of countless of soldiers, including Niles, who thankfully says nothing. Corrin immediately retreats in a lame effort to prevent suspicion, but carelessly rushing to her side in the midst of attack had already been enough to get him screwed. Leo remains silent as he follows his brother back to the castle, cursing himself. They're a few feet away from the grounds when he finally speaks.

"I know you love her."

Leo's heart nearly stops--"We all do, Leo."--he sighs out loud. "Our family is our treasure--and yes, you must do all you can to protect them. But you must not allow your duty as a brother to clash with your duties on the battlefield."

"I understand, Brother," he says solemnly. "I behaved foolishly. I hope your retainers aren't harmed because of that." 

"Laslow and Peri are both fine," he confirms, and his breathing evens. "If that was an apology, I accept it on their behalf. They understand our bonds…But I mean it, Leo: I cannot allow that to happen again. Our soldiers are too valuable and too few."

"I know, Brother." He does know. He understands. But Gods, if that arrow had been but an inch closer, she could have--

"Our sister is exceptionally valuable to this kingdom," Xander states, meeting Leo's eyes for only a moment. "I admire you for fighting so hard to keep her safe, but. Again."

The grip he holds on the reins of his steed tightens. "I won't slip up like that again, Brother. Forgive my ignorance."

A small smile twitches upon the taller man's lips, but fades quickly. "You follow your heart on the battlefield, Leo, I know--just make sure that big brain of yours keeps up with it."

* 

They are far past the age now where it's considered appropriate to bathe together, but sometimes, Corrin's sisters will insist on her joining them in the washrooms. The sight of Elise's bare bosom and the perfect grooming job between Camilla's thighs used to make her uneasy, but now that she's swallowing up her younger brother's cock on the regular, well. She supposes she can get naked in front of them once in a while. 

"Hurry up, darling," Camilla's voice echoes from the tub as Corrin looks herself over in the fogging glass. Leo'd done a good number on her neck, and chest, and Lords, her thighs too, so she can be thankful for once that Elise was fiddling too much with the tap that spurts giant soap bubbles. Camilla's got sharp eyes, but she's probably (hopefully) already halfway falling asleep now that Elise is washing her hair. Corrin sinks under the bubbles discreetly but it's already a little too late.

"Sister?" Elise pipes up and Camilla's eyes fly open. _Oh, here we go--dammit--_

The breath Camilla draws in is so sharp Corrin jumps like there's a snake in the water. "Darling, your neck!"

Corrin flushes, reminding herself to keep her wits about herself--"Y-yes?"

Both of them wade quickly over to her, pulling her hair back and running their hands all over her back and shoulders--her flesh sears with embarrassment. Elise starts pecking gently at the bruises. "Sister, what happened?"

"What _beast_ feasted on you?" Camilla asks, sounding far more intrigued than worried now. Elise squeezes her waist.

"Does it hurt?"

"No, nothing hurts," Corrin mumbles, pulling away, "I'm fine, really--"

Elise frowns. "Did something go wrong on the mission last night?"

Corrin opens her mouth to speak, but Camilla cuts her off. "Elise, darling--might you find a towel and fetch Selena for me? I believe I left my favorite lotion in my private quarters--I'm simply dying to have it after what a pain that mission was…" 

"May I have a bit of it too?" the blonde smirks and her sister pecks her forehead. 

"Of course. Run along, then." She watches Elise wrap a towel about herself and slowly turns back toward her pale sister with a gleam in her eyes. Corrin freezes. "Now then--"

"What," she says flatly, covering her bruised breasts but her lavender-haired elder dives right for them, softly pressing her mouth onto whichever marks on her neck she can see despite her yelping. " _Camilla--geez--_ "

"--with virgin ears absent, you and I can talk like _ladies_ \--"

"--Sister, w-whatever do you--"

A devilish giggle tickles her ear and Corrin groans. "I know you won't say anything in front of delicate Elise, but you don't have to hide the details from your big sister--"

"Sist--please, I don't--"

"--although if you're fucking one of my subordinates, we're going to need to have a talk, I've got to have at _least_ two things that are only mine--"

"Camilla," Corrin grunts, pushing wet hair from her eyes as she wrangles herself out of her grasp. "I'm doing nothing of the sort, I swear to you--"

She sighs in relief, sinking low enough to be eye level with Corrin's chest. "Mmm? Then who's leaving these _inspiring_ marks on my sister's delectable complexion?"

Corrin swallows. She needs to spit out a believable answer, and quickly--Jakob is too obvious--and too dangerous, Gods, _no_ , _not_ an option, he would make that a reality and she does not wish that at all--Laslow? Believable-- _very_ \--oh, but Xander would give him too much trouble if he found out--Keaton the Wolfskin? _Very_ believable by the looks of her marks, but still--although, maybe she could--or--or--

"Felicia," she blurts out, forgetting to breathe and instantly wondering what on earth kind of mess she just made for herself. Camilla's eyebrows dart up as a quiet oh falls from her lips--damn and blast, she's not going to buy it, shit, she can see the curiosity fading from her gaze--

She smiles. Widely and gently, with a sultry giggle and sway of her breasts, she smiles. Her arms pull Corrin in and she strokes her wet hair, all the while her heart flutters frantically--

"Women are magical, aren't they?" Camilla mutters, looking down at her through her long lashes. Heat rises in her cheeks as her sister inspects her neck, clicking her tongue. "My my, little Felicia…I wouldn't have guessed she had it in her."

"She's--full of surprises," Corrin chokes and she backs off, seemingly satisfied. Her smile is gentle and warm, melting her nerves just enough to finally relax in the water, but she still clears her throat to make a request. "Erm--please, Sister, if you could refrain from--"

"Sweet summer child, you needn't even ask," she finishes for her, winking. "We all have reputations to maintain…Never fear. Your secrets are always safe with me, darling."

She sighs heavily. "Thank you, Sister."

"Mmm you can thank me by rubbing that lotion on my--"

"Camilla--!"

*

Niles had seen it. 

He had said nothing in regard, but he's sure he had seen him kiss her. He tries his damnedest to be thankful that Xander hadn't turned his head a moment sooner, but the spark in Niles' eye won't leave his mind. That curious, knowing shimmer of intrigue is haunting him, but why?

Niles serves him with his life. Notoriously loyal to his master, more so than any subordinate has ever been to their liege. He would never breathe a word against his prince to anyone, not even to the King himself. If anyone were even close to knowing anything about--the current situation, Niles is the absolute best case scenario. So why does it frighten him so?

"My Lord."

Zero nods before entering his chambers, white hair falling over his eyepatch as he brushes his cape off his shoulders. Leo clears his throat, leaning on his vanity table. 

"Good evening, Niles."

"Felicia said it was urgent," he started, closing the door behind him. "Are you hurt?"

He smiles pitifully at his reflection. _Not quite yet_. "Niles, you know that I would trust you with my life."

"Pfff," Niles barely chuckles, "My Lord Leo…I wasn't prepared for such sentiment."

"I have a request," he starts, joking aside. His heart feels solid as a rock in his chest, it hurts--"Two of them, actually."

"Whatever you wish, Sire." 

"The first is to keep as close a watch on Corrin as you do on me," he says shakily, looking for a tell on his face, but he sees none until--"the second is to keep whatever you saw on the battlefield yesterday to yourself."

The evening glow from his window dances in Niles' mindful eye. He smirks ever so slightly and the panic makes bile rise in Leo's throat. "You claim to trust me with your life, yet you need to ensure that I keep my mouth shut about your affairs?"

He swallows audibly, furrowing his brow as he moves forward. "Niles, you must understand--"

"--that you're fortunate enough that it was this eye that caught you and not your brother's?" he barks; Leo can't tell if he's trying to be funny or scolding him, either way it sways him uneasily. The thief's face softens, but his eye dances over the worried lines in his master's face. "Apologies, my prince."

"No, you're right," Leo admits, feeling sicker by the second. "You're entirely right. That's why I must ask you…"

"Whatever your will, I'll carry it out, My Lord," he begins, but frowns. "The girl will never leave my sight, if that's your wish…but permit me to impart you with a word of caution."

He wets his mouth, barely blinking as he looks back at the older man. "Of course."

"If you go any further with this, there's only one thing I'm sure would happen," he struggles, like this advice hurts him to give. "That you will break her heart, and your own."

Leo clenches his jaw. He doesn't want to believe he could be right. "Please. Protect her, all the same."

He nods, folding his arms. "You have my word, my Lord." 

"Thank you, Niles," he says emptily. 

"If there's nothing else, then, my prince, I should resume my patrol," he says airily, turning the doorknob--Leo nods, swallowing tears.

"Yes, of course…goodnight, Niles."

The glint of his blue eye bores through him before the door is shut. "Goodnight."

**Notes for the Chapter:**

> that was a longer break than i intended but i'm glad to have my groove back. phew i missed writing this ;;


	8. Chapter 8

_"I insist you take this."_

__

_"…What's this about?"_

_"I swore to my prince that I'd protect you."_

_"Niles, what is--"_

_"He loves you. So much that I don't think he'll hold back any longer."_

_"I…"_

_"Please, princess. Allow me to fulfill my duty. Take it."_

*

_You will break her heart, and your own._

Leo's slender hands send ripples across the still water of his bath. He's been sitting in there for hours now, he guesses, barely moving, his subordinate's warning looming over his head like a bad hex, repeating itself over and over. The last thing he wants to do is believe it, to believe he possibly _could_ \--but words of warning never leave Niles' mouth without weight to them. His heart contests it, but he knows, he's known since before this all started: he cannot be with his sister beyond closed bedchambers.

At no more than five years old, he remembers being so openly enamored with Corrin--so charmed by her widening eyes and growing silver hair, gushing to his older siblings, "I want to be with Corrin forever! I love her!"

He remembers how unseemly his lamenting had been when Xander had to crush him with facts ("She is our sister, Leo, you cannot marry your family members as a prince!"), but Camilla would smile tenderly, seeing no harm in letting him play games--

Only now he's eighteen and he's not sure he wants to just play games anymore. He's watched her pleasure herself, he's kissed her, he's done all but fuck her now; after months and years of yearning to taste the sap from her bark, he's finally succumbed to his odious desires. He's had more of Corrin he'd ever imagined he'd get--

Yet the ache in his heart still remains. He pines for her even when he's in her bed, craves her even when they kiss. No matter how near she is to him, it still seems she's far beyond reach--a light atop a tower he cannot climb. This pain that can't seem to fade--the weight of reality crushing his heart--this is what Niles means. 

Leo splashes his face with water, his throat swelling as his eyes start burning. She can never truly be his. He fixates on the ceiling, barely focused on the cherubs and angels painted on its dome. He sighs. "I know, Niles." His voice echoes in his empty quarters, fancy faucets softly dripping into the emptying tub. He wraps his lounge robes about his waist, smiling helplessly at himself in the mirrors.

Corrin should still be awake.

**Notes for the Chapter:**

> phew i finally got my laptop running again. a short update to hold you over until next time, i've got heavy stuff planned and i want to carefully make sure it turns out the way i want it to. thank you all for your hits, kudos, comments, but most of all your patience.


	9. Chapter 9

**Summary for the Chapter:**

> there is no other sin for which i'd rather rot.

**Notes for the Chapter:**

> (grabs mic) we were born sick but i love it. amen amen

Nine, ten, eleven gongs bellow from the clock tower. Corrin stretches out on her bed, running her fingers over Niles' purple bottle. She clinks her nails against the glass, watching its syrupy contents swirl and bubble. She's seen a concoction like this before, on a night before Camilla had taken a soldier (or two) upstairs to her bedchambers. It's a hex, a protective spell, a shaman's potion--a back-alley contraceptive. Assurance that she would not become with child if she were to sleep with someone. The forming knot in her stomach tightens. 

She's grateful, truly, if she's being honest--Niles had saved her the trouble of needing to awkwardly ask her sister about precautions, lying even more about who she plans to take to her bed--but she hadn't been ready for that. Of course, she's been dreaming of it, and already so far down the black pit as they've ventured into, it's hard not to desire it more now: the true unity of sleeping together. Yet the painful pull on her stomach tugs whenever she thinks of the only thing that can stop her: that the farther they go, the more it will hurt when, inevitably, it ends.

A soft tear slides down her cheek and she wipes it away quickly. She's known this from the start. Leo is her brother, her blood and flesh: they can never marry. To start a family within your family is unlawful, and they're surely already testing treason by fooling around as much as they do. Words cannot explain how lucky they are that it was Niles who had seen that unsightly kiss on the battlefield; she can barely consider the world of trouble they'd be in if Xander hadn't missed it by three or four seconds without dry heaving. Yet the tears still come, stinging and pitiful, when she remembers that Leo's given ring will rest on another woman's finger one day. She will be by his side at his future wedding, but not in the white dress. Another head will wear the tiara, another name will bear the title. Another womb will carry his child. This is their unchanging reality, their unspoken understanding--and until now, with this potion in her hands, it's been so easy to blissfully ignore it.

Until now, she's been telling herself it's all just for fun; a game to exhaust the lust between blossoming prince and princess, yet pulling a servant girl into a broom closet for some quick head doesn't compare to the feeling of holding her beautiful brother in her arms after bringing him to the edge. What she'd believed to only be relief from tension is causing her anguish instead, addicting and bewitching, so unlike the things she sees around her. Camilla's eyes fade with boredom after she bids goodnight to the butler who'd made her bedroom walls quake only minutes before. Elise is given bouquets of flowers and glittering bracelets and teddy bears, yet her smile flashes for only a moment before she falls back to her studies and servants take her presents to her room. Xander's golden curls hang perfectly in place after an hour in an empty lounge with two noble ladies and no one can even guess whether he's fucked either or both of them until he asks Felicia to please take care to the stains on the chaise. No romantic encounter seems to shake any of her other siblings at all, yet parting with Leo after he's only fondled her breasts and kissed her like a sloppy teenager leaves her pining tearfully for their next meeting. Every time their lips part, she thinks only of how much she wants to hold him again--blindly believing that they always have tomorrow, forgetting that one day, they won't. With this bottle in her clutch now, she can't ignore the truth any longer.

(She downs the potion.)

He'll tell her she's witless again, Niles with his all-knowing eye, that there lies no certainty for them aside from their impending parting. She thinks of the onslaught of letters from the noble ladies across the country, their portraits lined up on a table before Leo to look over (Gods, it tastes like it smells, like dirt--). The time will come for him to choose a wife, eventually, and the jealousy will drive her mad (--it's hard to swallow, her throat itches--), but it's not that time now. Now, she has him and he is hers, if only indefinitely; now is all that's ever mattered to her.

_"It takes effect immediately. The curse will make you barren for a year. Only drink it if you're sure."_

(--she smacks her lips--the aftertaste is even worse, her tongue feels slimy--)

_"It's maddeningly exciting, in a way--succumbing to a pleasure that you know will only end in pain...I'm almost envious of you, princess...You're really letting it come this far? "_

(--she sips the elderberry tea that'd gone cold earlier--finally the gunk in her throat eases all the way down and she can rid her tongue of the acrid taste--)

The doorknob twists open. Corrin spits out her mouthwash into the basin. 

The smell of balmwood and vanilla seeps into her stuffy room, warming it. Leo's heavy stare bores into her, skin brightened by the glare of the night sky. He flashes a smile, closing the door slowly and locking it behind. She sighs.

_To my brother, my beloved--I succumb._

*

Corrin's expectant eyes twinkle in the dark and Leo grabs her face in his trembling hands, kissing her like he's starving and she mewls eagerly, grasping his robes and tugging them off. His fingers pull at the lacing of her dress as he presses his hips against her and the ruffles start sliding off her shoulders. She hooks her leg around his hip and pulls him down onto her bed, hungrily biting his neck as he feels moans escaping his throat. The moonlight glistens in her silvery hair; her flushed skin glowing under his palms. Swallowing an anxious lump, he lets his hands roam across her breasts, feeling her heart jump under his touch and it makes the color rise in his face so much and so fast that she giggles. She grazes her nails down his cheek and neck and rests her fingers on his collarbone, puckering her lips to invite a gentle kiss and he obliges, his tongue rolling over hers as he reaches down to feel if she's getting wet (she is). He groans into her ear, moving his palm over her crotch but she pushes him off--

Corrin sits up, moving herself to settle onto his lap and Leo's chest aches; his swelling cock twitches beneath her and she smiles and moans, rocking into him. Her dress is sliding down even more and he opts to do away with it completely, pulling it over her radiant head, watching the ribbons kiss the length of her neck before falling aside. Her chest and neck are pink as petals and she's so warm with her bare bosom pressed against his skin. Heat coils in his gut as she grinds into him, a slow, steady rhythm that makes his cock pulse. She says nothing, but jerks her head to the right, to the nightstand--to where an empty purple bottle lay on its side. He forgets how to breathe for a moment--

"Is that--"

"Mhmm." She smiles demurely, pressing a kiss to his knuckles. He makes a noise that's something between a laugh and a choke--

"Did you--"

"I did--"

"Corrin," he starts, but she bites on his bottom lip.

"Leo, if I'm going to Hell," she mutters against his mouth, "I need something worth burning for."

There's a tightness in his chest like tree roots seizing his very heart, spiraling about his veins and pulling them taut as his head reels and his fingers twist around her cascading hair. His lips envelope hers in his sincerest, sweetest kiss, eyes glassy from oncoming tears. He cups her face and she traces his mouth with her thumb and they stare at each other, a raw desire burning in their eyes--he can't hesitate anymore, not with his sister nearly naked on top of his thirsty cock--

"Sister," he grouses; he pushes the hair away from her eyes and thrusts upward a little and oh, her little moans-- "there is no other sin for which I'd rather rot--"

Corrin gasps, tottering back and forth atop his warming growth--

"--yet I'm sure that here in this bed with you," he shudders, feeling the wetness of precum leaking through what little fabric is left between them-- "…is the closest to Heaven I'll ever be."

He thrusts two, three fingers into her soaking-wet cunt, prodding as deep inside as he can and she growls into his ear, digging her too-long nails into his shoulders. Sweat drips down his neck as the heat around them flares; he unbuttons the modesty panel of his lounge pants--

"Brother..."

"Sister--" grabbing the small of her waist, he holds her steady with one hand while the other carefully, slowly guides his bloated member inside her--

Corrin screams. A guttural, piercing scream almost reptilian in nature reverberates off the stony walls and Leo's heart clenches, the last thing he wants to do is hurt his darling sister--she clings to him, trying to muffle her cries with her face in his shoulder--he starts to ease out of her, lifting her by her hips but she protests.

"Don't, don't a-aaah--AAURGH--fuCK, _don't stop_ \--"

"Sister, _sister_ ," he worries, despite how sublime her tightness feels around his length, oh _Gods_ \--

She pulls him forward to fall on top of her, wrapping her legs about his hips, taking deep breaths, pain still etched on the lines around her eyes but a smile stretching wide across her lips--

"I'll be careful," he promises, easing himself in and out of her slowly in their new position. He cradles her head and she pushes up into him impatiently, wincing in pain.

"I don't want--to be handled delicately--"

"And I don't want you to be in pain," he snaps, smirking knowingly. "I want it to feel good when I--ah, make a mess of you."

Corrin swallows visibly and moans as he smooths his hands over her stomach, massaging where he can feel himself deep inside her. Lords, she's so tense, oh it feels so good with her greedy eyes fixated on him. _Shh, shh_ , he strokes her hair, listening to her breathing even out, watching her muscles loosen and relax. Her groans are sounding more sensual now so he thinks it fine to quicken his pace; her walls are still tight around him but she's grinning madly now, giggling with elation. What little blood isn't in his cock now rises to flush his face.

"You--feel--so--nice, Brother," she punctuates his thrusts, squeezing his hands as she rolls her hips up into him. He moans at the compliment, throbbing inside of her. She arches her back and he can see her pulse flittering at the base of her neck.

"P-Please," she's begging, breathing raggedly--his heart bangs against his ribcage so hard it's making him dizzy--

"Please what," he gulps, the heat bubbling inside him growing positively unbearable as he watches her desperate face. He can still manage a wicked grin as he presses, "What do you need from your little brother?"

She quivers beneath him, whimpering, "I need you to fuck me--"

"Hmm?" he teases, sliding out of her almost completely, only the tip of his member still within--she squirms. 

She grips his neck, clenching her inner muscles and he's caught between an impressed laugh and a grimace--"I need my little brother to fuck me."

Leo flashes his teeth and groans in earnest, bending his head to plant a messy, wet kiss to her lips. "Then fuck you I shall."

The blonde pulls his shivering sister up and over to sit atop his cock again, adjusting so that he can lean back and admire her form adorned in the glittering starlight. He grabs a pillow to prop up his hips and holds her slim waist in place. 

"Be a good girl," he directs her, voice rasping, "and hang on tight."

With her sides in his firm grip, Leo starts fucking up into her, slamming his hips into hers and she almost collapses forward, howling in fervency. Her screeches ring mellifluously off the chamber walls and no choir or chorus can give him goosebumps like the ones that trail down his arms now, now with his precious sister's cunt so snug about his cock. He drives himself into her, pounding her fast enough to match his frantic heartbeat, electric tingles shooting up his spine with her every grunt, every squeeze of her hand. Thin red lines painted by her nails rake up and down his arms as he thrusts away, fixated on her mesmerizing face. The points of her ears burn red as happy, tired tears stream from her glossy crimson eyes and she begs him not to stop, _no, please, please give me more_. Her thighs are shaking and he's so engrossed with the bounce of her breasts and the harmony of her moans he almost wishes he'll never cum; he wants to stay with her like this forever, here in her bedchamber, their den of sin. 

Corrin grinds down into him in a mismatched pace, her voice trembling-- "Brother, Brother I--I'm going to--"

"A-aaah," he moans; he feels her muscles clamping around him, oh Gods she's close too-- "Sister--don't hold back--"

"Are--you--going to--cum with me, Brother?"

His heart is somewhere near bursting in his chest; it feels like firecrackers are about to go off in the pit of his stomach as he meets her starstruck eyes-- "Corrin, I--"

He pins her down again, pushes her flat against the bed and clutches her thighs as he plunges himself in and out of her, rubbing against her in a perfect angle. She howls savagely as he feels his climax throbbing into her, her clit pulsing against him as she rides out the throws of her orgasm. They hold each other tight, both groaning and wailing as if the only way to keep from falling down an invisible hole is to anchor themselves to each other. Leo loses himself in her eyes, gasping for air as he feels her start to calm down, chest heaving against her soft breasts. He holds her hands, fingers entwined with hers, rubbing his face into her velvety hair before kissing her reddened lips. 

"Brother," she says, eyes alight with tenderness. "I'm so happy, Brother."

He works a strand of sweaty hair behind his ear, offering her a tired smile. "I'm glad--that we didn't hold back." He rolls over on his back and pulls her close to his chest--she buries her face where his neck meets his collarbone, resting her hands over his heart. 

"To be close with you like this," she starts, voice straining, "is all I've ever wanted."

It's painful to close his eyes, but if he meets hers, he too, will crumble to tears--he knows what she thinks--Niles' gravelly voice echoes in his eardrums. "Shh. Shh--"

The tolling of a far-off bell strikes them both and Leo bolts upright in her bed, his sister clutching at the blankets--the clock tower? It doesn't ring past midnight, not until dawn--

"What--?"

Leo furrows his brow as he throws himself off the bed to retrieve his robes. "I can't believe it--"

"What's happening?" she frets, finding her gown and pulling it on--

A pounding at her door shakes them both--he knows he should probably dive to hide in her armoire, but something tells him it's--

"It's Niles, your highnesses," a muffled call from the other side of the wood gruffs. Corrin swings it open to let him in and he purses his lips at his master. 

"I went to your room first, and lucky I'm quick," he mocks him. Leo's cheeks flare up, but it's not the time--

"The war gong?" the prince panics, and Corrin's eyes widen.

"The castle is under siege," he tells him, moving closer with an unfamiliar spark in his blue eye. "They're here for Corrin."

**Notes for the Chapter:**

> (jumps up on a table) i'm straying (tapdances) so far from canon (shakes butt) and i don't even care (drops mic)


	10. Chapter 10

**Summary for the Chapter:**

> "always i will do what i must--to keep you safe."

"What do you mean, they're here for Corrin?"

Her brother clutches her arm as they follow Niles down the winding staircase to the armory, the clamoring and shuffling of Nohrian soldiers shaking the walls of the castle. They move in the shadows, avoiding the eyes of the maids and butlers, Niles' cape billowing behind them as he starts to explain--

"That mission the other day--Hoshidan soldiers claimed they recognized Corrin as their missing princess--"

" _What_?" Corrin scoffs at the idea--she pushes open the iron door--"What fairytale childishness--"

"Hoshido's eldest Princess has been missing over eighteen years," Niles tells her, dead serious, shoving the two inside and locking the entrance behind them--"and the Crown Prince Ryouma believes our kingdom kidnapped her. So he's making a bargain--"

"What does he want?" Leo snaps, already strapping himself into his armor--

"He's got a woman hostage," he answers nonchalantly and Corrin almost slaps him, stopping in the middle of buckling on her breastplate.

"A woman's in danger and that wasn't the _first_ thing you reported? How could you?"

"Do you really think Hoshidan dogs have the gall to kill a young woman in cold blood only to make a point?" he spits back. "Ryouma and his people have a reputation to uphold. _Think_ \--"

"Who is this woman he's holding captive?" Leo thinks to ask, sounding more curious than concerned. Zero smirks.

"A little bird I thought to be dead, long ago," he starts, thumbing over the patch on his eye. "The daughter of a mysterious woman your father so loved, years and years ago--do you remember Azura, my prince?"

Corrin furrows her brow in a fret, watching Leo's eyes widen in wonderment. "I--Azura…? She's still alive?"

He nods to his prince. "She lives. And the prince is suggesting a trade: a princess for a princess, or he'll kill her."

"He's bluffing," Leo insists, despite the rising color in his face, but Corrin shakes her head defiantly. "I don't want to take that risk."

"Then you'd better meet your brother at the eastern bridge, soon--there's already fighting--"

"I understand--"

"Niles, thank you, but--" Leo begins, but doesn't need to finish. In a silent agreement, the retainer leaves Corrin alone with him to finish preparations by themselves. Their soldiers' cries and hollers sound so distant from down there in their quiet seclusion. Her brother embraces her in the crepuscule, the heat from his face searing the still-sensitive flesh of her neck--

"We've got to go."

Thick tears well in the corners of her eyes as she pulls him into a needy kiss--"I don't want to. I don't want to leave you." His lips capture hers over and over, each kiss more impassioned than the one before as he pulls on the straying hairs that frame her face. He twists his fingers in her hanging ponytail and buckles one more strap around her arm that she'd missed.

"Azura needs us. Our family needs us," his voice cracks ever so slightly. He looks younger now than he has in ages with terror on his face, but he doesn't break. Not her steel-hearted little brother. "Remember your duty."

"I haven't forgotten," she assures him, stroking his soft hair. "I will do what I must. Always I will do what I must--to keep you safe."

Leo's bottom lip quivers for only a second as he winds his fingers around hers, gripping her tightly. "Don't let them take you--no matter what happens, promise me you won't surrender--"

"I promise," she kisses him again, breathing in his scent. Memorizing how splendidly his lips mold against hers, like they were crafted solely to fit to one another. "They will not have me, Hoshido will not have me--"

They leave the castle with reluctance, fingers entwined, magic thrumming in their bloodstreams. Storm clouds gather in the cracks of the sky where daylight should be breaking. The Crown Prince Ryouma of Hoshido stands armed with his family, the woman with sea-foam hair bound in ropes at their feet. The forgotten Princess of Nohr doesn't speak, does not beg for her life; only her golden eyes never leave Corrin's face. She does not know this woman, has never seen or heard of her before in her life, and yet the desire to protect her is overwhelming. She looks to Xander, to Camilla, both with longing on their faces--

"Corrin, fall back," her brother commands her, ignoring her hand glued to Leo's, an unfamiliar pain in his narrow eyes. Camilla's hands wrap suggestively around the base of her halberd, yet her eyes seem watery.

"There's nothing to fear, darling--"

Elise latches herself onto her waist, kissing the back of her neck where she can barely reach. "Sister--"

"Sister!" a chirp from across the river makes her head spin around--the tiny princess of Hoshido clenches her staff, rose-colored hair whipping about her face. Her eyes--and the eyes of the boy behind her--they're shaped almost suspiciously like her own--

Prince Ryouma's voice thunders across the field, breaking her thought--"Kamui!"

Azura finally struggles in her binding and Corrin wants to leap to her aide, yet there's warning in her golden stare-- _don't, not yet_ \--

The Prince speaks directly to her, in a language she's only read in books, only heard snippets of during fighting: "After years and years, we've finally found you, Princess Kamui of Hoshido."

The grip Leo still has on her hand twitches. Meekly, she addresses Ryouma from her stance a few yards away, in his language: "My name is Corrin, dear Prince of Hoshido, and Nohr is the only home I've ever known. Please, consider that there must be a mistake--"

"There is no mistaking it," he counters, stepping forward, electricity surging forth from his foreign blade. "You were taken from us--stolen--Queen Mikoto's first child, Princess Kamui. In turn, our men took Azura, daughter of Garon and Shenmei--"

Xander grimaces, the whines and gruffs of his steed making Corrin sway on the spot--"It's not true! Corrin, look at me, please--"

Azura's brilliant eyes draw her gaze instead. Corrin doesn't expect her to speak in the Nohrian tongue, but--

"Run. If you want the truth, you must run--"

The expectant faces of her siblings burn holes through the back of her head.

"This could be easy, Sister Kamui," Ryouma presses, impatient. "A princess for a princess, and this war could be over--"

Corrin has never been aware of the spaces between her fingers than when she draws her hands away from her brother's. Elise breathes out an incredulous gasp as she pries herself away, blade shining as she moves to strike Azura free of her confines. Swords unsheathe and bows are pulled taut on either side of the river as Azura clings to her arm. They run. As both families shout her two names, she runs with her, choking back sobs, remembering something silly in the midst of all this chaos: _big girls don't cry_.

Leo would spit these words after she'd get upset at him for teasing her. She'd stomp her feet and sniffle when he called her slow, when he told her she was nothing special. He'd been so envious of her in their youth, as she was so coddled and loved by all the nobility in the castle--oh how Camilla would scold him so fiercely for reducing her to a blubbering mess, but he'd just shrug it off. _She's getting too old for such fits_ , he'd say, his jealousy venoming his defenses. But she's never held it against him, only wanted to make him feel loved--

Silas's horse whinnies as she and the forgotten princess hop atop his saddle. Jakob and Felicia follow behind her and her childhood friend in an unspoken pledge to be by her side, no matter what--a promise she wanted to make to her brother, but it's too late. She tries not to notice that Leo doesn't chase after her. He's not far enough away yet that she can't see that he's crying. Little Leo, pompous brat of a sibling, heart of steel and skin thicker than bark, cries as she finds the loophole in their promise. Hoshido does not have her, but now neither does Nohr. 

_I'm so sorry, Little Brother_. She doesn't have time to wonder if they'll ever forgive her--if _he'll_ ever forgive her--but Azura's warm hands on her back tell her she's doing the right thing. 

She's doing the right thing, so she doesn't cry. Big girls don't cry.

But sometimes, they run.

**Notes for the Chapter:**

> still dancing on top of my table because aaayyyyyy fuck canon amirite
> 
> so this piece is officially finished! i am sad to end this one here buuuut the exciting news is that i'm definitely continuing this in another piece. will the continuation be as long as this one? i have no idea! i just know that this piece turned into something way more extensive than i originally intended and i'd like to do it the justice i'm imagining for it. i've got a few other pieces i'd like to work on before continuing this, but please look forward to part two in the near future. as always thank you for the support, i couldn't have done this without you, the readers <3
> 
> EDIT: also! if anyone is interested, i would love to host a thirst chat group on skype on friday, oct 9. my username is witchhearted--i'm on us central time, but i'm off all day long, so anytime is good for me. lemme know who's interested in the comments!


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